A time-interleaved digital-to-analog converter (TIDAC) uses N digital-to-analog converters (DAC) to produce an analog output signal whose aggregate bandwidth is N times greater than the output signal bandwidth of any DAC operating in isolation. In a typical TIDAC, a serial-to-parallel converter couples a digital signal x(n) with a bandwidth B into the DACs, which are arranged in parallel. Each DAC samples and holds the digital signal at a rate N/B, producing an analog voltage or current. A clock coupled to the DACs causes the DACs to operate on the digital signal at intervals staggered by a period T=1/B, such that the first DAC samples the digital signal at t=0, the second DAC samples the digital signal at t=1/B, and so on. A combiner coupled to the outputs of the DACs interleaves the outputs from the DACs to produce the fullband analog output.
Unfortunately, nonlinearities in the TIDAC introduce distortion into the fullband analog output. These nonlinearities include mismatches in gain, phase, and/or offset (bias level) between different DACs in the TIDAC as well as nonlinearities of the individual DACs. In some cases, the amount of distortion in the analog output can fluctuate due to environmental perturbations that affect the mismatch(es) between DACs in the TIDAC. At present, there is no way to compensate effectively for such distortions in the analog output of a TIDAC due to the nonlinear responses of DACs in the TIDAC.